iOS SDK，Objective-C，只能显示一个单元格

我有一个用户输入的文本字段，然后我用NSKeyedArchiver保存它并将其拉出以在表上查看，但每次我在文本字段中输入内容并保存它时，它会替换单元格中的第一项，我希望它将其添加到表中

在NewEntry.m中，我使用

- (IBAction)saveButton:(id)sender {




int i = selectedSegment.selectedSegmentIndex;

app = [[UIApplication sharedApplication] delegate];

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];

[userDefaults setInteger:i  forKey:@"category"];





if (i == 0) {

   // [userDefaults setObject:titlefield.text forKey: @"titlehomework"];
// [userDefaults setObject:detailstextfield.text forKey:@"detailshomework"];

    NSMutableArray *contactArray;

    contactArray = [[NSMutableArray alloc] init];
    [contactArray addObject:titlefield.text];
    [contactArray addObject:detailstextfield.text];

    [NSKeyedArchiver archiveRootObject: 
     contactArray toFile:datafilePath];


}

else if(selectedSegment.selectedSegmentIndex == 1) {
    [userDefaults setObject:titlefield.text forKey:@"titletextprojects"];
[userDefaults setObject:detailstextfield.text forKey:@"detailsprojects"];

}
else if (selectedSegment.selectedSegmentIndex == 2){
    [userDefaults setObject:titlefield.text forKey:@"titletextappointments"];
    [userDefaults setObject:detailstextfield.text forKey:@"detailsappointments"];
}
else if (selectedSegment.selectedSegmentIndex == 3){
    [userDefaults setObject:titlefield.text forKey:@"titletextevents"];
    [userDefaults setObject:detailstextfield.text forKey:@"detailsevents"];

}

else if (selectedSegment.selectedSegmentIndex == 4){
    [userDefaults setObject:titlefield.text forKey:@"titletexttodolist"];
    [userDefaults setObject:detailstextfield.text forKey:@"detailstodolist"];
}

/*[userDefaults synchronize];
titlefield.text =@" ";
detailstextfield.text =@" ";
NSLog(@"selected segment %i", i);*/

/* UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Task saved!" message:@"You're all done." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, selectedSegment.selectedSegmentIndex];
[alert show];*/

[[NSNotificationCenter defaultCenter] postNotificationName:@"ValuesChanged"
                                                    object:self];


[self dismissModalViewControllerAnimated:YES];



}

NewEntry ViewDidLoad：

- (void)viewDidLoad
{
[super viewDidLoad];
if (__managedObjectContext == nil) 
{ 
    __managedObjectContext = [(StaticTableAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
    NSLog(@"After managedObjectContext_: %@",  __managedObjectContext);
}




NSFileManager *filemgr;
NSString *docsDir;
NSArray *dirPaths;

filemgr = [NSFileManager defaultManager];

// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(
                                               NSDocumentDirectory, NSUserDomainMask, YES);

docsDir = [dirPaths objectAtIndex:0];

// Build the path to the data file
datafilePath = [[NSString alloc] initWithString: [docsDir 
                                                  stringByAppendingPathComponent: @"data.archive"]];

// Check if the file already exists
if ([filemgr fileExistsAtPath: datafilePath])
{
    NSMutableArray *dataArray;

    dataArray = [NSKeyedUnarchiver 
                 unarchiveObjectWithFile: datafilePath];

    //titlefield.text = [dataArray objectAtIndex:0];
  //  detailstextfield.text = [dataArray objectAtIndex:1];

}





}

新条目ViewDidUnload：

 - (void)viewDidUnload
{


[self setTitleTextfield:nil];
[self setCategory:nil];
[self setDetailstextfield:nil];
[self setTitlefield:nil];
[self setTitlefield:nil];
[self setSelectedSegment:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;

}

在表控制器中，我在这里称之为： tableview：

- (void)viewDidLoad
{
[super viewDidLoad];
//  [self fetchRecords];  
if(tablesubtitles == nil && tabledata == nil){
tablesubtitles = [[NSMutableArray alloc]init];

tabledata = [[NSMutableArray alloc] init];

}    

NSFileManager *filemgr;
NSString *docsDir;
NSArray *dirPaths;

filemgr = [NSFileManager defaultManager];

// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(
                                               NSDocumentDirectory, NSUserDomainMask, YES);

docsDir = [dirPaths objectAtIndex:0];

// Build the path to the data file
datafilePath = [[NSString alloc] initWithString: [docsDir 
                                                  stringByAppendingPathComponent: @"data.archive"]];


// Check if the file already exists
if ([filemgr fileExistsAtPath: datafilePath])
{
    NSMutableArray *dataArray;

    dataArray = [NSKeyedUnarchiver 
                 unarchiveObjectWithFile: datafilePath];


    titlestring = [dataArray objectAtIndex:0 ];
    detailsstring = [dataArray objectAtIndex:1];



    [tabledata addObject:titlestring];
    [tablesubtitles addObject:detailsstring];
    }






}

以及：

***********更新*************** 因此，在saveButton中，它应该是：

  NSMutableArray *contactArray;
   contactArray = [NSKeyedUnarchiver 
       unarchiveObjectWithFile: datafilePath];

   // contactArray = [[NSMutableArray alloc] init];
    [contactArray addObject:titlefield.text];
    [contactArray addObject:detailstextfield.text];

    [NSKeyedArchiver archiveRootObject: 
     contactArray toFile:datafilePath];

    // NSDictionary *stuff;

---

问题是您正在创建一个新的可变数组，在其中放入一项，然后将该数组存档到您的文件中。这将取代以前的一切

要添加新项目，您需要先取消阵列存档，然后添加到该阵列，然后存档新阵列

---

这里似乎也有一些核心数据代码，如果您打算使用核心数据，那么您自己进行归档没有什么好处

在这个问题中有大量无关的和注释掉的代码。你应该把它编辑到你关心的部分，人们会更愿意阅读。哦，我有点理解。那么，您是指saveButton方法吗？我明白你的意思，但不确定在哪里是的，那是我唯一能看到你使用档案的地方。首先需要像在viewDidLoad方法中那样取消归档，然后添加到该数组中。您可能需要使用unarchiver数组创建一个可变数组，我认为unarchiver返回一个不可变的NSArray。我运行了它并更改了objectAtIndex 2和3，但得到的错误是数组没有第三个索引，没有那么大

  NSMutableArray *contactArray;
   contactArray = [NSKeyedUnarchiver 
       unarchiveObjectWithFile: datafilePath];

   // contactArray = [[NSMutableArray alloc] init];
    [contactArray addObject:titlefield.text];
    [contactArray addObject:detailstextfield.text];

    [NSKeyedArchiver archiveRootObject: 
     contactArray toFile:datafilePath];

    // NSDictionary *stuff;